Wavelet Based Characterization of Vertebral Trabecular Bone Structure from MR Images of Specimen at 3 Tesla Compared to MicroCT Measurements

Trabecular bone structure and bone density contribute to the strength of bone and are important in the study of osteoporosis. Wavelets are a powerful tool to characterize and quantify texture in an image. In this study the thickness of trabecular bone was analyzed in 8 cylindrical cores of the vertebral spine. Images were obtained from 3 Tesla (T) magnetic resonance imaging (MRI) and micro-computed tomography (muCT). Results from the wavelet based analysis of trabecular bone were compared with standard two-dimensional (2D) structural parameters (analogous to bone histomorphometry) obtained using mean intercept length (MR images) and direct three-dimensional (3D) distance transformation methods (muCT images). Additionally, the bone volume fraction was determined from MR images. We conclude that the wavelet based analyses delivers comparable results to the established MR histomorphometric measurements. The average deviation in trabecular thickness was less than one pixel size between the wavelet and the standard approach for both MR and muCT analysis. Since the wavelet based method is less sensitive to image noise, we see an advantage of wavelet analysis of trabecular bone for MR imaging when going to higher resolution